1. Field of the Invention
The present invention generally relates to graphics processing and more specifically to drawing a stipple line while preserving the stipple phase for segments of the line.
2. Description of the Related Art
Stippled lines are drawn with patterns of dots and dashes (stiplets) to give the lines some texture, allowing lines representing different features to be distinguished. Often a single stippled line is drawn as a continuous line strip made up of line segments. This requires that the stiplets match up from one line segment to the next. Therefore, the stipple “phase” is tracked from line segment to line segment. The stipple phase is a measure of the position of a point on the line within the stipple pattern.
Computing the phase for the segments of a line strip is performed serially since the stipple phase at the start and end of each line segment depends on the stipple phase of the previous line segment in the line strip. When all of the line segments are processed by a single rasterization pipeline the stipple phase may be easily tracked and updated for each line segment. When parallel rasterization pipelines are used to render the stippled lines in parallel, there is not a serialization point where the stipple phase can be computed.
Accordingly, what is needed in the art is a system and method for computing line stipple phases in parallel.